diff --git a/source/player/player.cpp b/source/player/player.cpp
index 2e1ab65d8..50ceecdb6 100644
--- a/source/player/player.cpp
+++ b/source/player/player.cpp
@@ -511,10 +511,12 @@ int CPlayer::getHeightFromGround(int _x,int _y,int _maxHeight)
 	if(isOnPlatform())
 	{
 		DVECTOR	platformPos;
-		platformPos=m_platform->getPos();
+		platformPos=m_platform->getPosDelta();
 		DVECTOR newPos = getNewCollidedPos();
 
-		height = newPos.vy - Pos.vy;
+		// since collision was detected in the LAST frame, we must check to see where the platform has moved to in THIS frame
+
+		height = newPos.vy + platformPos.vy - Pos.vy;
 
 //		if(height<-_maxHeight)
 //		{
diff --git a/source/thing/thing.cpp b/source/thing/thing.cpp
index f2d301b68..bf05f8b62 100644
--- a/source/thing/thing.cpp
+++ b/source/thing/thing.cpp
@@ -783,7 +783,10 @@ int		CThing::checkCollisionAgainst(CThing *_thisThing, int _frames)
 			{
 				thatPos.vy = getNewYPos( _thisThing );
 
-				s32 verticalDelta = abs( _thisThing->getPosDelta().vy );
+				// vertical height change is the sum of the maximums of BOTH objects
+				// potentially, one object could be falling down through another object that is moving up
+
+				s32 verticalDelta = abs( _thisThing->getPosDelta().vy ) + abs( this->getPosDelta().vy );
 
 				if ( thatPos.vy - _thisThing->getPos().vy >= -verticalDelta )
 				{